Answer: D
Explanation:
First, we know that the acceleration is defined as the ratio of change of the velocity.
This means that, if we have a change in the velocity, then we also have acceleration.
And by Newton's second law we know that:
F = m*a
Force equals mass times acceleration.
So if we have acceleration different than zero, then we should also have force different than zero.
So we must have a nonzero net force acting on it.
The correct option is D
